Computer tomography (“CT” or “CAT”) scanning systems are generally known in the art. The first CT scanners used a source of X-rays directed as a beam and a single detector to detect the amount of X-rays passing through the scanned object. During a scan of an object, the source and detector are passed through a line on the object, then the source and detector is moved relative to the object and scanned through another line on the object. Data is collected from each scan into an array that is manipulated by a computer to provide a variety of images of the object. These provided images are called reconstructions or reconstructed images.
So called “second generation” CT scanners use a fan-shaped X-ray beam and a corresponding plurality of detectors arranged along the fan. Similar to earlier CT scanners, a second generation CT scanner may be moved relative to the scanned object to collect a full set of readings on the object. In between scans, the object may be rotated to expose a different portion of the object to the X-ray source. In other prior scanners, the object may be rotated during translation or movement across the scanner.
Several known algorithms exist for creating the reconstructed images of an object scanned by CT scanners. These algorithms use various geometric values relating to the physical CT scanning system to manipulate the collected scan data into the reconstructed images. Sometimes, however, the reconstructed images of an object contain undesirable visual aberrations or distortions called artifacts that render the final images difficult or impossible to use or understand. Often times, these artifacts are due to imprecise geometries of the CT scanning system. It is known to manually manipulate the scanning systems to reduce or eliminate such artifacts for any given scanning system; such manual manipulation, however, is time consuming, error prone, and requires a trained operator.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions and/or relative positioning of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of various embodiments of the present invention. Also, common but well-understood elements that are useful or necessary in a commercially feasible embodiment are often not depicted in order to facilitate a less obstructed view of these various embodiments of the present invention. It will further be appreciated that certain actions and/or steps may be described or depicted in a particular order of occurrence while those skilled in the arts will understand that such specificity with respect to sequence is not actually required. It will also be understood that the terms and expressions used herein have the ordinary meaning as is accorded to such terms and expressions with respect to their corresponding respective areas of inquiry and study except where specific meanings have otherwise been set forth herein.